extension ExtPose

Viewport Resizer: Responsive Website Testing Tool

CRX id


Description from extension meta

Test your site's responsiveness with this powerful screen and window resizer and resolution emulator. Perfect for modern web design.

Image from store Viewport Resizer: Responsive Website Testing Tool
Description from store Viewport Resizer is a tool to test any website’s responsiveness. Just install the extension, go to the page you want to test and check all kinds of screen resolutions of the page. The smartest way to share your defined environment of devices and breakpoints directly with your team and client. This tool should not replace a real device simulation. It rather helps you, your team and client testing statuses, transitions, text length etc. throughout different device types.

Latest reviews

  • (2023-08-28) Liu ShengQi: 能保存设置吗。每次开页面都要点多一次
  • (2023-02-16) Konstantin .G: настройка тут: https://lab.maltewassermann.com/viewport-resizer/ выбираете девайсы/дописываете свои и перетаскиваете кнопку Your customized bookmarklet в избранное отлично работает
  • (2022-11-16) Jochem: Easy, working, but one type with an example on different screen sizes would be great, like material.io had (though their Resizer tool isn't working at all, bad stuff)
  • (2022-10-12) Vicky Lahkar: This extension has saved my life. Literally. Recently, our workplace website was upgraded and this new site could no way be adjusted to a mobile screen display. But by using Kiwi browser + this extenion, I did get what I wanted. An thereby could avoid the purcahse of a tablet!
  • (2022-05-23) Митя ДраКоан: Единственная проблема расширения это Access denied: Cross-domain security error на защищённых сайтах Полезная в обычных случаях копия скрипта работает даже оффлайн, но в случае защиты от кроссдоменных атак не разрешает запускаться из фрейма. Известно, что из JS это никак не решить (это правильное поведение), поэтому это не проблема расширения. Для таких случае просто нужно искать что-то другое.
  • (2022-03-17) Diego Zurita: La califico con 1 estrella porque no sirve para trabajos en Local. Era para lo que lo necesitaba, una lástima. Aún así funciona perfecto en webs que están en servidores.
  • (2022-02-03) Alice G: Too bad it doesn't work for local files. I wanted to use it as a dev tool...
  • (2022-01-26) Varun 'Scarfoot' C: SO USEFUL! Thank you so much!
  • (2021-12-13) Danny Ben Shitrit: Excellent extension. Does not require any privileges, resizes just the viewport and works for resolutions larger than your own screen. The animate feature is great for seeing all sizes one by one without lifting a finger. Recommended for developers.
  • (2021-11-18) Frank Xu: 关闭按钮不能用啊
  • (2021-09-28) Ramon Henrique: Por algum motivo não funcionou, só no Youtube que testei, mas no meu site nem sequer abriu
  • (2021-09-24) Robin Li: 方便好用,可快速切換並預覽各種尺寸的畫面,方便響應式開發測試。
  • (2021-09-06) Eskerinola: Use this extension to test web design. It's the best I've tried. The animation option is fantastic. Great job!
  • (2021-09-06) François Duprat: Doesn't work properly...
  • (2021-08-31) Tormi Talv: Nothing alse than Apple screens? No options? Useless!
  • (2021-05-24) Kieu Manh: It's very useful and clean. Thank you so much <3
  • (2021-05-19) bloodys spammers: 💥 DOES NOT WORK IN MOBILE BROWSER!!! 💥
  • (2021-04-10) Александра Худова: Плюсы: 1. Меняет размер вьюпорта, а не браузера целиком 2. Удобный и приятный интерфейс Минусы: 1. Иногда вообще не работает 2. При включении иногда ломает анимацию на сайте, приходится обновлять страницу 3. Нет возможности сохранить свои пресеты разрешений
  • (2021-04-03) Ali Mehdi (MADs): Well done with the job you've done here. I highly suggest to add basic screenshot and saving custom resolutions option. Thank you .
  • (2021-03-28) Max il byondo: Fantastic. I use with Yandex browser on an Android phone and it's the ONLY WAY to view a true "desktop version" of many websites. I know it's not its primary use, but would it be possible to have an option for hiding the toolbar? Thank you!
  • (2021-03-10) Igor Sholdanenco: Не работает
  • (2021-03-02) Bidrohy Hasan: Best extension for responsive design testing.
  • (2020-12-31) Márk Ambrus: it does not resize the browser window BUT On every second click it was opening shady websites, probably malware.
  • (2020-12-09) Ana Gabriela Herrera Rosas: Es muy bueno, a veces con alguna versión se puede trabajar pero en general es bueno
  • (2020-11-28) Olivier Lesire: This tool is by far the best in its category. I love the "Animate" option that allows you to instantly test your work on ALL screen sizes, from the very small smartphone screen to the very large desktop screen, with a single mouse click. Congratulations to Malte Wassermann, creator of "Viewport Resizer - Responsive Testing Tool": Thank you Malte, your work is fantastic!
  • (2020-10-23) Peter Kionga-Kamau: Useless. Clicking it just shows a link to the stupid Chrome web store, options and inspect are greyed out. No functionality. No instructions. No point.
  • (2020-10-11) Катя Буянова: СУпер
  • (2020-09-20) Muthu Krishnan: I did not know this tool existed. Exactly what I wanted !! Great
  • (2020-09-15) M.R.M. Munna: very halpefull and Amazing extension
  • (2020-06-27) Mauricio Vuljevas: Please Improve the toolbar icon, y really ugly!, the extension, it's amazing, contrats. (4 stars because of the ugly toolbar icon haha)
  • (2020-01-12) Javier Piraquive Calderon: Excelente aplicación, no funciona con LOCALHOST, debe estar el sitio en un servidor externo.
  • (2019-10-20) Dezso Markon: It's better then the rest of the similar extensions, however on reload resets the size of the viewport, so it's kind of useless for development. Would be nice to implement this just like like Firefox does.
  • (2019-09-03) Tim Graham: Great extension. The 5th star wasn't given due to having to store custom sizes in a bookmark which isn't user friendly. Apart from that, it's the best as it only the resizes the viewport instead of the entire window like other extensions.
  • (2019-07-22) Pete Leigh: Was really excited when I seen this, makes my developing go a lot faster 5/5
  • (2019-02-27) Kaisma Penn-Titley: Inconsistently works for me, that is, I click on the icon and it does not respond or prompt me with options. When it does work, it resizes to the selected specification but is very frustrating when I am constantly clicking and it's not doing anything.
  • (2019-02-16) Phoenix Kiula: Should work with localhost or file system as well, where most of the testing is done. It seems to require a functioning website, which is silly.
  • (2018-10-15) Samir Bipecka: I also love that it does not resize the browser window but only the viewport.
  • (2018-09-15) HSH Home: thank u so much for this great tool. it is not just valuable, it is fun too! The Animate button LOL. Thank u for the great creation.
  • (2018-06-01) Pratik Thakkar: One of the best Developer extensions for testing on multiple devices. Best part is that it does not resize the browser window. I strongly recommend this tool
  • (2018-05-11) Sergio Acosta: I love that it does not resize the browser window but only the viewport, unlike most other resizing extensions.
  • (2018-05-10) ศุภวัฒน์ ตันมณี: ชอบที่สุดตั้งแต่ใช้มา ถ้าสามารถ edit custom size และ range ในการทำ animation ด้วยจะเยี่ยมมาก --------- Best re-sizer tool for me, please make custom size easier (via live textbox) and configurable animation range for better
  • (2018-05-04) Andi Wahyu Saputra: love it a lot
  • (2018-04-19) Marco Chieffi: Vi prego di aggiornare la lista dei dispositivi
  • (2018-04-19) Rogério Dec: Excellent!The Best!
  • (2018-03-27) Tomaž Krt: Clicking the icon does nothing.
  • (2018-03-09) Helen Lazareva: love this tool, extremely helpfull
  • (2018-03-09) Damir Males: Very Good app If it allows a screen size pictogram between 320 and 600px it would be great :)
  • (2018-02-23) Manali Prasad: Easy and useful
  • (2018-02-15) R. Muhamad Dwi Rizki Lazuardi: Very good, the only extension that work well to test even large display resolution. More precise than chrome device toolbar to develop pixel perfect website. The only missing feature is to save multiple custom resolution.
  • (2018-01-27) Andrew Gibbs: Does nothing!

Latest issues

  • (2022-12-01, v:1.1.9) Sergio Vazquez II: Viewport Resizer - Custom Size BUG
    There is a BUG in Viewport Resizer that consistently RESETS the custom viewport size ANY time you navigate. This is NOT the expected functionality, and does NOT happen when viewing ANY of the other sizes. https://imgur.com/a/93cxmLc
  • (2022-07-13, v:1.1.9) Edward Cox: Unable to use with Shopify store
    Access denied: Cross-domain security error Is this something that I need to take up with Shopify or is there a way to tell Responsive Design Tool that it's safe? Thank you
  • (2022-02-17, v:1.1.9) Quran-Instituut al-Husayn: Not showing on a specific site
    Hi the resizer wont show on my site shop.alhusayn.nl Do you know why this is not working.
  • (2022-01-31, v:1.1.9) ZestCitron: Can't use it anymore
    Everything was working fine but now I just have a white page when I click on the extension. I'm on macOS Monterey (Apple M1) and Chrome is up to date.
  • (2021-12-07, v:1.1.9) Edward Cox: Does not support Shopify pages
    Access denied: Cross-domain security error every single time. How frustrating. Edward
  • (2021-06-13, v:1.1.9) Mohamed Alkhalifa: Mac Chrome
    Hello! Your extension looks amazing! But I was unable to use it. Nothing happens when I click the extension icon on Google Chrome (Mac). Whats weird is that when I tried to create a custom extension on your website, the dropdown was visible and functional. But when i go back to another window and click the extension button, again nothing happens.
  • (2021-06-08, v:1.1.9) orinoco: Changeable presets!
    Would be so nice for testing other devices that aren't in the current list. Great extension btw, it's the only one I found that can mimic viewports bigger than the current resolution, which is pretty cool.
  • (2020-07-16, v:1.1.9) Dave Giffney: Not working
    Does not display toolbar using Mac Chrome: Version 84.0.4147.89 (Official Build) (64-bit) OS X: 10.15.5
  • (2020-07-16, v:1.1.9) Marcia Alegria: no funciona
    clickeo la extension y la primeera vez funciono pero despues de eso no funciono mas
  • (2020-07-13, v:1.1.9) Christoph Päper: Website
    There apparently is a website for the extension at https://lab.maltewassermann.com/viewport-resizer/ but it is not listed in the Chrome Web Store. Since the extension has no Options page, it is also not accessible from there.
  • (2020-04-24, v:1.1.9) Tomasz Zemsta-Piasecki: Problem with google chrome and windows 7 operation system (64-bt)
    It doesn't work
  • (2020-04-02, v:1.1.9) June Smith: testing local files
    I apologize if you received this before. When testing an html file saved locally I get a "Cross-domain security error". can this extension even be used for local files? thank you for your time.
  • (2020-01-16, v:1.1.9) Brian G: Custom Sizes
    Is it possible to add custom screens/devices?
  • (2020-01-08, v:1.1.9) Millie Hernandez: Problem
    Everything was working fine but now when I click on the extension the panel does not appear for me to switch between different sized screens. So I'm not able to use the extension at all.
  • (2020-01-02, v:1.1.9) Shiblee Mehdi: Removed the extension but still specific URL opens in mobile view
    Hi, I was testing an URL. Later on removed this extension but still my testing URL opens in mobile view. How can I go back?
  • (2019-10-31, v:1.1.8) Poonam Yadav: Viewport Resizer
    Viewport Resizer not working properly...
  • (2019-02-15, v:1.1.8) Marc Thiong'o: cant save custom size
    Trying to save a custom size but there's no way to do so or its well hidden. Otherwise the app is great!
  • (2019-02-04, v:1.1.8) Robin Richey: Stopped working.
    With the latest release of windows 10 the extension no longer opens.
  • (2018-12-21, v:1.1.8) Dania al khalil: how it works ?
    Hello ,i added it to chrome and open my website and then once i click on the view port resizer icon -> The website is gray and doesn't open anymore -> a gray page only Please advice Thank you
  • (2018-10-19, v:1.1.8) Adam Spiers: Doesn't work on medium.com
    When I visit a medium.com page and click the icon, it just reloads the page but the resizer strip doesn't appear.
  • (2018-05-10, v:1.1.8) ศุภวัฒน์ ตันมณี: Animation configurable
    It's better if can set custom size for animation function
  • (2018-05-10, v:1.1.8) ศุภวัฒน์ ตันมณี: Custom size faster
    Please make live input for custom size
  • (2018-03-19, v:1.1.8) Mark Parra: loads blank bar
    when i initiate the plug in the top bar loads but nothing loads within. blank bar with no presets.
  • (2018-03-19, v:1.1.8) Marc Scheithauer: Keine Funktionalität
    Die Erweiterung hat leider keine Funktionalität in Chrome 65 unter Mac OS X High Sierra ...
  • (2018-01-11, v:1.1.8) melscott scott: my lap top screen is
    my lap top screen is to small for a robot I purchased how can I shrink the the robot to fit into my lap top screen please thank you m p s


80,000 history
4.1767 (266 votes)
Last update / version
2024-06-04 / 1.2.1
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